One of the limitations of current permanent magnet systems for current magnetically-guided minimally invasive surgical procedures is that they lack the ability to provide variable force. In many applications, however, variable force is crucial for optimal manipulation and control. As an example, a physician may need to vary the amount of force they exert on a magnetic tip catheter, depending on the anatomy and type of catheter procedure. As another example, a magnet-tipped endoscopic microscope benefits from variable magnetic force control. If the microscope is pressed too forcefully against tissue, the tissue is too deformed to provide quality images; however, if the microscope is not pressed forcefully enough against tissue, the microscope does not make sufficient contact with the tissue to obtain quality images. An ideal magnetic system for such procedures would provide an appropriate amount of contact force between the microscope and the tissue to provide optimal image quality.
Current permanent magnet systems for magnetically-guided minimally invasive systems require large magnets, which complicate attempts to modulate the magnetic force with reasonable bandwidth due to their large size and high inertia.
Thus, there is a need in the surgical field to create an improved system and method for guiding a magnetically-guided medical instrument. This invention provides such an improved system and method.